46 DISPOSITION TO SECURE A TERRITORY 



here or a duller red there, as the case may be — 

 and though these differences may not be 

 sufficient to enable us to pick out a bird at 

 a distance, they are nevertheless conspicuous 

 when it is close at hand. Then again there is 

 variation in the song ; and the more highly 

 developed the vocal powers the greater scope 

 there is for variation. But even the phrases of 

 a simple song can be split up and recombined 

 in different ways. If one were asked casually 

 whether the different phrases of the Reed- 

 Bunting's song always followed one another in 

 the same sequence, the answer would probably 

 be that they certainly did so, whereas the bird is 

 capable of combining the few notes it possesses 

 in a surprising number of different ways. And 

 lastly, there are differences in just the particular 

 way in which specific behaviour, founded upon 

 a congenital basis, is adapted by each individual 

 to its own special environment. Racial pre- 

 paration determines behaviour as a whole, but 

 the individual is allowed some latitude in the 

 execution of details which are in themselves of 

 small moment — the selection of a particular tree 

 as a headquarters and a particular branch upon 

 that tree, the direction of the distant excursion, 

 and the direction of the limited wanderings 

 within the small area surrounding the head- 

 quarters which in the course of time determine 

 the extent of the territory, are matters for 

 each individual to decide when the occasion 

 for doing so arises. Moreover instances of 

 abnormal coloration or abnormal song are not 



